Ore-roasting kiln.



IIEETB--SHEET v l l.

PATBNTED AUG. 29, 1905.

Worm/frs J. MONAB. ORE ROASTING KILN.

APrLIoATIoN FILED 11.11.29, 1905.

W/TNESSES:

PATENTED AUG. '29, 1905..

J) MONAB. om; ROASTING KILN. APPLICATIONy FILED MAB.29.11905.

4 SHEETS-SHEET 2.

R 0 T N rC V N JAMES MC N M2y fiswii ATTORNEYS PATE1-P12B11- AUG.' 29, 1905.

J. MONAB. ORE ROASTINGKILN. APPLIogTIoN FILED MAR. 29 1905.

4 SHEETS-SHEET 3.

/m/E/vrof? JAM Es MC NAB ATTORNEYS No. 798,524. PATENTED AUG. 29, 1905. J. MG'NAB.

ORE ROASTING KILN.

APPLIUATION FILED 11.13.29. 190s.

4 SHEETS-*SHEET 4.

WIT 8858.'

ENTTEE sTATEs l PATENT oEErcE.

ORE-ROASTING Kumi.

Specification of Letters Patent.

Patented Aug. 29, 1905.

Application filed March 29,'1905. Serial No. 252,684.

To all whom it may concern:

Be it known that I, JAMES MCNAB, a citizen of the United States, and a resident of Catonsville, in the county of Baltimore and State of' Maryland, have invented a new and useful Improvement in Ore-Roasting Kilns, of which the following is a specification.

This invention is an improvement in oreroasting kilns, and particularly in kilns designed for use in extracting sulfur from pyrites in the manufacture of sulfuric acid; and the invention consists in certain novel constructions and combinations of parts, as will be hereinafter described and claimed.

.In the drawings, Figure l is a perspective View, parts being removed and others shown in section, of a kiln embodying my invention. Fig. 2 is a vertical longitudinal section thereof. Fig. 3 is a sectional top plan View on about line 3 3 of Fig. 2. Fig. 4 is a vertical section on about the line 4 4 of Fig. 2. Fig. 5 is a cross-section on about the line 5 5 of Fig. 2. Fig. 6 is a detail perspective view showing the side slabs for use at the outer side of one of the end fireplaces. Fig. 7 is a detail perspective view showing the side slabs for use between two fireplaces. Fig. 8 is a detail perspective view of the keyblock, having an opening for the discharge of the gases. Fig. 9 is a detail perspective view of one of the arch-slabs used in forming the arch of the fireplace. Fig. 10 is a detail perspective view of one of the key-slabs used in forming the fireplace-arches. Fig. ll is a detail perspective view of the arch end blocks. Fig. l2 is a detail perspective view of one of the door-frames of the fines-burning flue, and Fig. 13 shows av somewhat different arrangement of the fines-burning flues for use in very large plants; and Fig. 14 is a detail perspective view, on a relatively enlarged scale, illustrating the arch.

In carrying out my invention I provide a series of fireplaces A and A', arranged in a battery alongside each other and in two rows, the fireplaces A and A being arranged back to back, as will be understood from Figs. l, 3, and 4 of the drawings. The fireplaces A and A are alike, and a description of one will answer for all. I make each fireplace, as

shown in Figs. l, 2, 3, and 4, with a grate B, an ash-pit B', an ash-door b, and a feed-door b, and I construct the fronts of the fireplaces with a metal door-frame,over the top of which is put a large fire-clay slab B2,fo1ming a lintel and operating to prevent the heat inside of the fireplace from warping and buckling down the upper edge of the door-frame, which is a common objection to kilns now in use. The side walls C and the back wall D of the fireplace may be made of brick in the usual way to a point above the fuel-line, and then the side walls are extended upwardly by means of fire-clay slabs E e or E c', as shown in detail in Fig. 6 and applied in Figs. l and 2, these slabs being beveled on their sides at their upper edges at E2 and provided with tongue-and-groove devices Ff and E* at their meeting ends, so they may be fitted and interlocked together, and having at their ends projecting tenons c2, by which they may be built into the brick structure at the front and rear of the fireplaces, and so held securely in place. The beveled surfaces E2 form the seats or bases from which the arched tops of the fireplaces spring, as best shown in Figs. l and 2. The back walls D of the fireplaces are extended upwardly by means of the arched end blocks F and f, curved on their Lipper sides at F and f and provided with tongues F2 and grooves f2 at their meeting ends, whereby they are interlocked, as will be understood from Figs. 2 and 11 of the drawings.

The fireplace-arches are preferably built of arched slabs G, the key-slabs H, and the keyblocks I, which are shown in detail in Figs. 9 and l() and are applied as shown in Figs. l and 4 and operate to provide an arch which is composed of fewer and larger blocks than those ordinarily employed and which are so arranged and connected as to form a much more durable arch than is provided by the brick construction in ordinary use. A serious defect of the fireplaces now commonly employed in kilns of' this character is the general weakness of the side walls and arch, which soon break, being made of ordinary fire-brick with a few left out to form a gashole. If one of these bricks becomes loosened, it will readily be seen that the arch is materially weakened and will soon fall down. By my construction the side and back walls which divide the adjacent fireplaces arc made at their upper ends of two large fire-clay blocks keyed together at their meeting ends and arranged above the ore-level in the fireplace, which ore is usually banked about thirty inches above the grate-bars of the fireplace. I also construct the arch of large fire-clay slabs Gr, H, and I, the slabs G being in the form of rectangles and the slabs H being sloped or tapered on one side /i to form a key IOO IIO

and the block I being tapered on its sides e' and provided with a gas-hole v1 for the passage of the gas into the main gas-linfa, which extends above the lireplaee of each row, as will be understood from Figs. 1, 3, and 4 of the drawings. This makes a very strong construction of arch and one which can be more easily built, at less expense, than those commonly used, will last much longer with fewer repairs, and is altogether more desirable than the form of arch now commonly employed in the construction of fireplaces of this character.

The main gas- Hues A3 and Ai extend, respectively, above the rows of fireplaces A A and receive the gases therefrom through openings I in the key-blocks, these key-blocks being arranged at the inner or rear ends of the arches over their respective fireplaces, as will be understood from Figs. l and 4 of the drawings. At their ends the Hues A3 and A4 discharge at A5 to the niter-oven A6, in which the niter-tubes A7 may be arranged, as shown in Figs. 2 and 3. From the niter-ovens the gases pass inte the Hue A7, thence they discharge at AS to Glover towers, and thence into the large lead chambers, where the gases are condensed into sulfuric acid, as is well known to those skilled in the art. As no improvement is claimed herein in the Glover towers or the lead chambers, it does not seem necessary to illustrate the same in the aecompanyingdrawings. Supplemental Hues o3 and ai extend, respectively, above the main gas- Hues A3 and A", are separated therefrom by the fire-clay tiles J, which form a Hoor for the Hues a3 and ai, and are rabbeted together at their joints jte prevent the escape of the gases directly from the Hues A3 and A4 to the supplemental flues a3 and a". The supplemental Hues c3 and are designed for burning the so-ealled fines7 usually amounting to about ten per cent. of pyrites, made in crushing the pyrites, and which cannot be used in the lumpkilns. The disposition of these fines is a difficult problem where high-grade copper ores are used, as it is not practical to mix these lines with the low-grade ores used in the automatic furnaces for burning the fine ores containing no copper. I therefore provide the supplemental Hues a3 and the fines in which are heated from the main gas-Hues below to evolve the sulfurous gases which pass from the front end of the Hue a3 to the front end of the Hue ai and thence back and discharge at a5 to the rear end of one of the main gas-fines, and, mixing with the gases in said Hue, pass forward to the niter-oven at the front of the main Hue, as will be understood from Figs. 2 and 3 of the drawings, in which the course of the gases in the supplemental Hues is indicated by arrows. The lines are roasted in the supplemental Hue c3, and the flue a* forms a passage by which the gases evolved by the roasting of the ores in the Hue a3 are conducted to the rear end of the main gas-Hues, to be carried thence to the niter-ovens. At the front or delivery end of the Hues c3 I provide a dustehamber K, which operates to purify the gases before they enter the conducting-Hue and pass thence and discharge into the rear end of the main gas-Hue to mix with the gases l'herein.- The tops of the flues a3 and a4 are shown as consisting of plates L, and on these is put the line ore L to be dried before charging the same into the feed-hoppers M of the gas-generating Hue a3. rIhese hoppers M may be made of sheet-iron and provided with a plug M', (see Fig. 2,) and after the charge of Hue ore is put in the Hue a3, through the hopper M, the plug M is quickly inserted and some green ore put in upon the plug, which lutes the hopper and preventseseape of gas. rIhe lines-roasting Hue c3 is provided at its front with discharge-openings N on a line with the bottom of the rabbeted Hoor J of the said Hue and provided with a door N', by which the opening N may be closed when desired. A hopper O may be hooked at O beneath the opening N and applied whenever it is desired to scrape the burned fines from the fines-roasting Hues a3, this hopper O discharging to the stationary sheet-iron s out O2 as shown in 9 Figs. l and 4 of the drawings, such spout discharging into a wheelbarrow or other means for carrying 0H the refuse.

It will be understood from the foregoing description and illustration that I utilize only about one half of the upper surface of the main gas-Hue for actually burning the lines and utilize the other half as a return or dust chamber, making the gas from the fines return back to the rear end of the kiln, where it then drops into the lower or lump-ore gas- Hue, thence into the gas-pipes, &c. This is for an ordinary-sized acid plant of, say, three hundred thousand cubic feet capacity; but where it is larger and consists of, say, double the above size plant or more and of course making a much larger amount of fines this plant can be modified by taking two sets of kilns anddividing the upper Hue, as shown in plan, except to leave out the dividing-wall in center of dust or fines kiln and use the whole IOO IIO

surface of one set of kilns, about four to nine by ninety feet, for a burning-surface for fines and utilize the upper Hue in the other set of kilns as the dust-chamber, the gases in the burning-kiln traveling to rear end of kilns and crossing by connecting-Hue into rear end of second set of kilns and dust-chambers, as best shown in Fig. 13 of the drawings. This dust or return Hue is important, as it operates to prevent the dust from the fines passing into the towers and choking up and interfering with the process, and the simplicity of the construction and the ease with which the fines-burning Hue may be cleaned out at any time and the great economy of construction through the burning of the fines will commend itself to those skilled in the art. In

ISO

practice the upper fines-burning and return fines are built of ordinary red brick, lined inside with fire-brick and the sides bound with stays, secured on top with a rod binding' front and back, and at the bottom the buck-stay may be secured on the rod which binds the front and back fines of the ore-kilns on top, and on the top of this dust-kiln T-bars may be provided and sand or fines L" be piled to conserve the heat.

In practice the castings for the front doors of the fireplaces may be made about six feet long and suitablysct in the walls, the ends of the castings being behind the buckstays and the castings being made with suitably-faced fronts, so that they fit tight to avoid escape of gas andthe entry of air.

In practice a set of Yfireplaces consists of fifteen on each side, placed back to back and making a length of about ninety feet, so that the upper fiue having' the fines-burning section will be about ninety feet long, thus utiliZing' a considerable surface above the main gas-flue, and the fireplaces arranged side by side, as will be understood from the drawings and foregoing description.

The slabs forming the arches of the fireplaces may be made of fire-clay, soapstone, or similar material. A

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The improvement in ore-roasting kilns herein described comprising' the series of fireplaces arranged in a battery side by side and extending' in two rows with the opposite fireplaces back to back, said fireplaces being provided with the crown-arch composed of arched slabs, key-slabs having tapered sides, and a key-block having tapered sides and an opening for the escape of gas, the main gasfiues extending' above the fireplaces of each row and receiving the gas from the key-blocks of' the several arches, the niter-oven to which the main gas-fines discharge at one end, the finesburning flue extending longitudinally above one of the main gas-fines, means for supplying the fines to said burning-fluc, and the return or dust fiue connecting at one end with the forward end of the hues-burning fiue and extending thence rearwardly alongside the fines-burning fiue and discharging at its rear end to one of the main gas-fines, substantially as and for the purpose set forth.

2. The ore-roasting kiln having a series of fireplaces, a -rnain g'as-fiue extending above the fireplaces and receiving the gas therefrom, and a fines burning flue extending above the main gas-fine and discharge connections between the fines-burning flue and the main gas-fine, substantially as set forth.

3. rIhe combination in an ore-roasting kiln of a series of fireplaces, and a main gas-flue extending' above and receiving the gas from 'said fireplaces, and a fines-burning 'flue extending above and heated by the main gasflue, substantially as set Jforth.

4. In an ore-roasting kiln, the combination of the main gas-flue a fines-burning flue extending` longitudinally above the main gasflue and having a section in which the fines are burned, and means for supplying fines to said section, and a discharge or dust-collecting section receiving the gas evolved from the fines and conducting the same to a suitable discharge point, substantially as described.

5. An ore-roasting kiln comprising in combination a main gas-fine, and a fines-burning' fiue extending above the main gas-flue and havingI a return-section, and a burning-seetion'and having the return-section communieating at one end with the discharge end of the burning-section and discharging' at its other end to the main gas-Hue, substantially as set forth.

6. rIhe combination in an ore-roasting kiln of a series of fireplaces, the main gas-fiue extending above the same, the fines-burning fiue above the main gas-fine, and having an outlet or discharge door, a hopper receiving the discharge from the said door, and a spout to which said hopper discharges, substantially as set forth.

7. In an ore-roasting kiln the combination with the fireplaces having rear and side walls, and arches having gas-discharge openings near said rear walls, a main gas-flue extending above the fireplaces and receiving the gas therefrom and the fines-burning fiues extending above the main gas-fine, substantially as set forth.

8. The combination ofthe fireplace side walls and rear wall extending' above the ore-level, the arch-blocks on the rear wall and interlocked at their meeting ends, the top slabs fitting' on the side walls and interlocked at their meeting ends and beveled on their sides at their upper edges, the arch springing between the beveled edges of the opposite top IOO IOS

slabs, and consisting of the arch-slabs, the

key-slabs, and the key-blocks, substantially as described.

9. An ore-roasting kiln having a fireplace whose side and end walls above its ore-level consist of sections or slabs having tongue-andgroove connections at their meeting ends, and an arch springing between the top slabs of the side walls, substantially as set forth.

10. The combination with the body of a kiln-wall extending above the fuel-level of the slabs forming top portions of said walls and interlocked at their meeting ends, substantially as described.

1l. The combination of the fireplace having the rear and side walls the'slabs forming the top portions of said walls, and the arch-slabs G, key-slabs H, and key-block I having an opening for the escape of gas, the 'said slabs G and H and the block I constitu ting an arch springing between the top slabs of the side walls of the fireplace, substantially as Set forth.

12. A fireplace having a top arch composed of arch-slabs G, l ey-slabs H, and a key-block I havingI an opening for the escape of gas, substantially as set forth.

- 13. The combination in an ore-roasting kiln of a battery ofreplaces consisting' of two rows ranging side by side, the niter-oven at one end of the battery of fireplaces, the main gas-flue extending above the rows of lireplaces and discharging' at one end to the nitcroven, the lines-Hue having a burning-section extending above the main gas-flue and a return or dust-collecting section receiving the gas from the burning-Hue and discharging at its rear end to one of the main gas-lilies, sbstantially as set forth.

14. In an ore-roasting kiln the combination with the main gas-flue of the fines-flue above the same and comprising a fines-burning section having baffle devices adjacent to its discharge end, and a dust-collecting or return Hue communicating at one end with the discharge end of the fines-burning fine and discharging at its other end to the main gas-flue, substantially as and for the purpose set forth.

15. An ore-roasting kiln having' a series of fireplaces, a main gas-flue receiving the gas from the said fireplaces, and a fines-burning 'Hue heated from the main gas-Hue, substantially as set forth.

16. The combination of a Yseries of fireplaces, a main gas-fine receiving the gases discharged from said fireplaces, and a finesburning flue exten'ding longitudinally parallel with the main gas-fine and adjacent thereto and heated by the said main gas-due, substantially as set forth.

JAMES MCNAB. llfitnesses:

J oHN A. HENKUS, (no. WV. D. WIGHT. 

